Hospital sheeting



Juiy 4, 1933. s. H. RUBiN El AL HOSPITAL SHEETING Filed Jan. 11, 1933 lNVENTORS.

ATTORNEY Patented July 4, 1933 UNITED STATES PATENT OFFICE SOLOMON H. RUBIN, OF BROOKLINE, AN D JAMES J. CLIFFORD, OF READING,

MASSACHUSETTS i HOSPITAL SHEETING Application filed January 11, 1933. Serial No. 651,134.

Rubberized hospital sheeting has been used for a great many years and consists of a cotton sheeting base fabric coated on one or both sides with rubber. Usually the rubber coatings are finished in such a Way that they are given a very smooth slippery surface. This may be done in several ways well known in the rubber art as, for example, by applying a dusting or drying coat of starch, varnish,

or a surface drying agent to the rubber coati serious objection to hospital sheeting of both the single and double coated types is the difficulty of holding it in the desired loca- 1 tion on the bed against its tendency to slip out of place and'to wrinkle as the patient moves in bed. With a view to obviating this difiiculty it has been proposed heretofore to fasten the corners .of the sheet to the springs or to the frame of the bed, but this expedient has not proved entirely effective in preventing the objectionable wrinkling under the patients back and it has the further disadvantage of requiring considerable time to adjust whenever the bedding is changed or the bed is made up.

The presentinvention deals particularly with these conditions. It aims to devise a hospital sheeting in which the tendency to slip out of. position and to wrinkle under the patient will be substantially obviated.

The nature of the invention will be readily understood from the following description when read in connection with the accompanying drawing, and the novel features will be particularly pointed out in the appended I claims.

In the drawing, Figure 1 is a perspective view of a portion of a hospital sheet constructed in accordance with this invention and illustrated on an enlarged scale with the plies of the sheet partially separated at one corner;

v Fig. 2 is a perspective view of the edge portions of another embodiment of the in vention;

I Fig. 3 is a plan view of still another form of the invention but on a small scale;

Fig.4 is a sectional view on the line 4-4,

'- 5 Fig.3;

the prior art practice is necessary.

- tress.

Fig. 5 is a sectional-view of still another form which the invention may take; and

Fig. 6 is a sectional view of portions of the sheet shown in Fig. 2, with additional marginal strips.

Referring first to Fig.1, the article there. shown comprises a sheet 2 of fabric which may consist of ordinary cotton sheeting, such as that commonly used heretofore. Bonded securely to one side of this sheet is a rubber 00 coating 3, usually made relatively thin, and serving largely to waterproof one face of the fabric sheet 2. This coating may consist of a thin film of rubber exactly like those used on one or both sides of hospital sheetingmade in accordance with the prior art practice, or it may consist of some other flexible waterproof coating compound havin a nitrocellulose base, or made from one o the cellulose esters. Such compounds are readily obtainable in the market. So far. as these two plies are concerned, however, no departure from The opposite surface of the fabric sheet 2 is covered by a layer 4 of rubber which has very difl'erent characteristics from that of the coating 3.. Preferably it consists of a layer of sponge rubber of considerable thickness, say for example, one-sixteenth of an inch, or thereabouts, and this layer has a surface which offers great resistance to slipping over another surface whether of fabric, rubber, or other materials. I

It is contemplated that this product will be made in webs of indefinite lengths which later will be cut into sheets of any desired size. In using such a sheet, it will be stretched across the mattress in the usual way and the opposite edges will be tucked in between the mattress and the spring with the layer of sponge rubber 4 in contact with both the upper and lower surfaces ofthemat- Due chiefly to the high frictional surface characteristics of the layer 4 this sheet-can slide on the surface of the mattress 05 (only when considerable force is applied to reason, and, partly also due to the increased I thickness of the sheet as compared to those used heretofore, there is practically no danger of the sheet wrinkling under the patients back. If the margins of the sheet are well tucked under the mattress, the weight of the patient adds greatly to the difiiculty of displacing the sheet or permitting it to wrinkle. The fact that the sponge rubber coating engages both the top and bottom faces of the mattress where they bend around the opposite edges of the mattress greatly increases the resistance of the sheet to slipping. Such a sheet, therefore, aifords all of the protection given by those heretofore used, while at the same time avoiding the very serious objections to prior art hospital sheeting of this general character, eliminating any necessity for tieing or fastening the sheet to the mattress or the frame of the bed, and affording a surface for contact with the bed sheet which may have the same characteristics as those to which the patient is accustomed. In addition, the layer 4, which is very p0- rous, spongy and elastic, provides a cushion through which the irregularities in the mattress cannot be felt as readily as with the common types of rubberized sheeting, and

which, therefore, adds materially to the comfort of the patient.

Such a product can be manufactured by several different methods. For example, the rubber plies can be made independently of each other and then bonded to, or combined with, the intermediate fabric ply. Usually, however, we prefer to make the rubber plies 3 and 4 directly on the intermediate fabric ply. This may be done, for example, by applying the rubber directly to the fabric by calender rolls or by using a spreader coat-- ing machine of the type well known in the rubbery industry. According to the method which we prefer at the present time both sides of the fabric 2 are first coated with a rubber cement compound in a spreading machine, and an additional rubber coat is then put on to one surface of the fabric by means of calender rolls, a firmer adhesion of the main body of the rubber to the fabric being produced. in this manner than if a calender coat only were applied. The compound so applied may be of the standard type now used for hospital sheetings, and the surface can be dusted with starch, varnished with alcohol, or treated in any other desired mannor as the fabric comes off the calender rolls to give it the smooth surface finish desirable for-the upper coating 3.

To the opposite side of the fabric we apply a rubber compound which preferably has a high rubber content and contains gas forming ingredients such as those used in the rubber art in making sponge rubber. Such a compound may include a high percentage of rubber, with suitable proportions of sulphur, accelerator, pigments, and the like, and gas forming salts, such asammonium bicarbonate, sodium bicarbonate, and others. Usually, also, it is preferable to dust this layer of rubber with zinc stearate, or some other dusting ingredient, which will melt during vulcanization and be absorbed by the rubber.

After the fabric has been coated on both sides it is then vulcanized. In a typical process the heat of vulcanization may be in the neighborhood of 240 to 265 F and in any event should be suflicient to cause the salts or other gas forming ingredients to break down and liberate gases which will form a great multitude of pores, cells or bubbles in this body of rubber and thus produce the extremely porbus and spongy effect characteristic of rubber of this type. Some of the cells produced by the gas forming constituents of the compound will break through on the outer surface of the layer 4 and these, combined with the irregularities in the surface caused by the presence of gas bubbles which do not break through, give to the outer surface of this layer the high frictional characteristics which are particularly desirable for the purposes above described. In addition, a rubber compound made in this way has a somewhat tacky surface which, although not sticky, nevertheless adds greatly to the resistance which such a surface offers to sliding movement'across another surface, and which is important in causing the sheeting to cling to the mattress, and in preventing the relative movement between the mattress and the sheeting that would result in causing wrinkling when used on a bed. It seems probable, also, that the resistance to sliding movement of the layer 4 of the sheet across the surface of the mattress may be aided, at least under some circumstances, by the suction created in those cells which have broken through to the surface of the layer 4 and act somewhat in the nature of suction cups.

While we prefer to cover substantially the entire area of one surface of the fabric 2 with a sponge rubber layer 4, a less expensive product having some of the advantages of that above described can be made by coating the side margins only of the sheet with sponge rubber. Such a construction is shown in Fig. 2 in which the intermediate ply 2 is coated on both sides with films of rubber 3 like the upper coating in Fig. 1, and strips 5-5 of sponge rubber are securely bonded to the opposite margins of the web, these strips being of, say, two or three inches, or more, in width so that when the opposite edges of the sheet are tucked under the mat tress these strips will come in contact with the mattress along those regions that bear product, however, lacks the cushioning properties of the article shown in Fig. 1.

In some cases hospital sheeting is made in certain definite sizes instead of in the form of a roll or web, and in such an event the spronge rubber strips can be secured to all four edges of the sheeting, as shown in Figs. 3 and 4, the strips being indicated at 5, and the construction of the sheet otherwise being like that illustrated in Fig. 2. For some purposes, also, it may be unnecessary to coat both surfaces of the fabric. Such an arrangement is shown in Fig. 5 in which the fabric 2 has a coating 3 like that shown in Fig. 1 applied to its upper surface only, the lower surface being uncoated over much of its area but having marginal strips 5" of sponge rubber cemented or otherwise securely bonded thereto. These arrangements secure many of the advantages of the preferred construction illustrated in Fig. 1, but at a considerably reduced expense of manufacture.

Fig. 6 shows a product like that illustrated in Fig. 2 except that marginal strips 5, of sponge rubber have been applied to the upper as well as the lower surface of the rubberized sheeting, so that when the sheet is in place the marginal strips of sponge rubber on both sides of the sheet will come in contact with the under surface of the mattress on one hand and with the bed spring on the other hand, making slipping practically impossible. If the draw sheet is tucked under these marginal edges they also assist in holding said ing substantially the entire area of one side of the sheet, or strips of this material to serve somewhat the same purposes, other rubber compositions can be used to produce the frictional resistance or non-slipping effect of the sponge rubber layer on the mattress. For example, a crepe rubber sheet and various compositions known in the rubber industry for imitating crepe rubber efl'ects can be used and will produce an article greatly superior to those commonly employed heretofore. It is also contemplated that the non-slipping eflect can be obtained in other ways. However, we prefer the construction shown in Fig. 1 both because of the added comfort which affords the patient and also because of its all around superiority. We believe that we are the first to devise a hospital sheeting (by which we mean any sheet material for covering or protecting a bed mattress) having nonslipping properties and we intend, therefore, to claim the same broadly. While, therefore, we have herein shown and described a preferred embodiment of our invention, it'will be understood that the invention may be em? bodied in other forms without departing from the spirit or scope thereof. For example,

while we have described the base of our material as a common cotton sheeting fabric, it will be understood that various other sheet materials could be substituted for it, the nature of this base not being an essential part of our invention but any suitable base material bein used. Also, the thickness of the sponge ayer or strips, or the equivalent parts, naturally will be suited to the require ments of personal preferences in individual situations. 7

Having thus described our invention, what we desire to claim as new is:

1. A hospital sheet comprising a base of water-proof sheet material and a coating of rubber applied thereto, said coating having high surface frictional properties and being of sufficient thinness to afford great flexibility and pliability, said coating covering at least the marginal areas of the sheet adjacent to the opposite edges thereof, whereby to hold the sheet firmly against slipping and wrinkling when said margins are tucked under the mattress.

2. A hospital sheet comprising a base of sheet material, a waterproof coating on one side thereof, and a coating of rubber on the opposite side, the latter coating having high surface frictional properties, and being of sufficient thinness as to afford great flexibility and pliability.

3. A hospital sheet comprising a base of sheet material, a waterproof coating on one side thereof, and a coating of sponge rubber on the opposite side thereof, the latter coating having a surface which offers high resistance to slipping, and being of sufficient thinness as to afford great flexibility and pliability.

4. A hospital sheet comprising a base of sheet material having approximately the entire area of one side thereof covered with a flexible waterproof coating securely bonded thereto, approximately the entire area of the opposite side being coated with a vulcanized rubber compound securely united to the fabric and having an outer surface which offers great resistance to slipping, and which is of'sufficient thinness as to afford great flexibility and pliability.

5. A hospital sheet comprising a sheet of fabric having approximately the entire area of one side thereof covered with a flexible waterproof coating securely bonded thereto, approximately the entire area of the opposite side being coated with a layer of sponge rubber securely united to the fabric and having an outer surface which offers great resistance to slipping, and which is of sufficient thin- 1ioiess as to afford great flexibility and pliaility.

6. A hospital sheet comprising a sheet of fabric having approximately the entire area of one side thereof covered with a flexible waterproof coating securely bonded thereto,

marginal areas of the opposite side of said fabric carrying a coating of vulcanized rubber having high surface frictional properties, and of suflicient thinness as to afford great flexibility and pliability, said marginal areas being sufficiently great to engage a least two surfaces of the mattress lying in different planes, when said areas are tucked under the mattress.

7. A hospital sheet comprising a fabric, both sides of which are coated with a flexible waterproof material securely bonded to the fabric and protecting the fiber of the fabric, marginal areas of said sheet, on one side thereof, carrying a relatively thick coating of sponge rubber, the surface of which offers great resistance to slipping, and which is of sufficient thinness as to afford great flexibility and pliability, said marginal areas being sufficiently great to engage at least two surfaces of the mattress lying in different planes, when said areas are tucked under the mattress.

8, A hospital sheet comprising a sheet of waterproof fabric having a coating of rubber applied thereto, said coating having high surface frictional properties and being applied to marginal areas of the sheet which tuck undera mattress, said marginal coatings being of such width as to engage at least two surfaces of the mattress lying in diflerent planes and hold the sheet firmly against wrinkling, when tucked under the mattress, and being sufficiently thin to afford great flexibility and pliability.

9. A hospital sheet comprising a sheet of fabric, a waterproof coating on one side of said fabric, both sides of said sheet having margins coated with rubber which offers high resistance to slipping, the coating on one side being adapted to engage the mattress and that on the other side adapted to engage the draw sheet, said marginal coatings being of such width as to hold said hospital sheet firmly against slipping when said margins are tucked under the mattress and being sufficiently thin to afford great flexibility and pliability.

In testimony whereof we have hereunto signed our names to this specification.

SOLOMON H. RUBIN. JAMES J. CLIFFORD. 

